Batteries shorted out...

[notsure]

Got two new VTC5s yesterday and both of them shorted out as soon as I put them in my Sigelei 30w today. I have to admit that I had always been a little curious about what to expect when that happened. Now that I know I sure hope it doesn't happen again. Luckily they held up, but they get really hot really quick.

More importantly other than a little bit of burn on my hand everyone survived and the mod is still in working order.

 

[vapire]

I would test that mod on a scope if you have one. Give the batteries a huck as well.

 

[notsure]

Don't have a scope. Any suggestions on where to get one?

 

[TygerTyger]

hope your hand is ok..... I'm speculating here but I'd check really carefully at the positive connection on the mod..... is there a chance that the battery's positive post was touching metal other than the positive pin? Some mods are meant for button tops only.... is this one of them?

 

[TygerTyger]

Actually, I just did a quick search..... seems to be a well-documented and common problem. Many vendors are recommending button-tops only in this mod as the flat-tops (especially Sony apparently) barely make contact, and if they do, you run the risk of shorting. Some are using the small round rare-earth magnets to simulate a button-top, but be aware that if the magnet shifts, you'll have the same problem.

 

[notsure]

Yea I checked it out, and it does look like it may have made contact and is what caused the short. I had been using efest batteries in it previously which are flat top and haven't had any issues. Being a little concerned that it may have been the flat top battery I did put a button top in it to see if the it still worked and it does, but still not sure I am going to continue to use it just out of caution. Unfortunately I am not sure what to do to make sure it's safe to use.

 

[notsure]

Thanks Tyger, I was just doing some searches as well and found quite a few posts with reports of the same problem.

 

[TygerTyger]

Efest flattops might be ok if the top is shaped a bit differently. Some flattops are higher than others. The mod should be ok as long as nothing in it fried, but of course I have no way of advising you on that from here. If it was me, I'd probably just use batteries in it that are safer for its design, and test it thoroughly in use, removing the batteries whenever I'm not using it for a while to make sure there are no further issues. Best of luck to you and hope it turns out ok.

 

[vapire]

Good to know you figured it out. In absence of a scope try your old batteries for a bit then compare them to the new one if you plan to use the magnet fix. An oscilloscope is going to run you $80 for an old analog dual channel 50 MHz and a digital equivalent will run you about 350 450 easily. Sorry for what ever reason I assumed you had one.

In any case test the batteries and the mod. Make sure the batteries aren't comprised maybe use them in another mod if you have them make sure they aren't getting warm quickly and signs of dents on the negative.

Though as tyger said your best option is to use proper batteries for it. I personally wouldn't risk it could end up bad.

Thanks Tyger, I was just doing some searches as well and found quite a few posts with reports of the same problem.

 

[notsure]

I'm going to poke around for a oscilloscope, it's worth a few bucks to know everything is in safe working order.

I have several other mods, but I am hesitant to even mess with these two batteries at this point.

Tried to post a pic of the batteries, but the file is apparently too large. I

 

[notsure]

Found this oscilloscope on amazon.... thoughts?

 

[jae]

Naw, i'd think you should only really need a halfway decent multimeter to check for continuity. You should NOT have continuity with the switch disengaged. Loose or crossed wires, loose or bad components could also cause problems. (But hell i don't know, i use mechs these days and haven't soldered a joint in probably decades.)

With a mod like that i'd probably use protected batteries which are in my limited experience a bit longer. But IMRs have a safer chemistry so get a good pair of nipple-tops and see if that helps.

But i really don't know much, so literally any random person is likely to be far smarter than me and maybe has much, much better advice.

 

[notsure]

Yea, have a button top AW IMR in it now and I have used it a few times and the mod seems good. Haven't used it a lot, I tend to have a couple of mods going when I'm at home and jump around a bit so I've not messed with it much. I did check the batteries with a multimeter and both of them checked out ok. Both tested right around 4.0v

 

[vapire]

We'll if he actually damaged the you wouldn't only check for coninuity.

Naw, i'd think you should only really need a halfway decent multimeter to check for continuity. You should NOT have continuity with the switch disengaged. Loose or crossed wires, loose or bad components could also cause problems. (But hell i don't know, i use mechs these days and haven't soldered a joint in probably decades.)

With a mod like that i'd probably use protected batteries which are in my limited experience a bit longer. But IMRs have a safer chemistry so get a good pair of nipple-tops and see if that helps.

But i really don't know much, so literally any random person is likely to be far smarter than me and maybe has much, much better advice.

Naw, i'd think you should only really need a halfway decent multimeter to check for continuity. You should NOT have continuity with the switch disengaged. Loose or crossed wires, loose or bad components could also cause problems. (But hell i don't know, i use mechs these days and haven't soldered a joint in probably decades.)

With a mod like that i'd probably use protected batteries which are in my limited experience a bit longer. But IMRs have a safer chemistry so get a good pair of nipple-tops and see if that helps.

But i really don't know much, so literally any random person is likely to be far smarter than me and maybe has much, much better advice.

That's why I suggested the scope to see if he gets a proper signal and that the fuse and caps are still working properly. Though I know you wouldn't need a scope to test a fuse. Though scope is not generally needed unless you want to go hardcore test rigs or modding.